1. Field of the Invention
The claimed invention discloses a method of determining a coordinate on a micro dotmap, and more particularly, to a method of determining a coordinate on a micro dotmap according to a moving vector.
2. Description of the Prior Art
Please refer to FIG. 1, which illustrates scanning a displaying medium printed with a micro dotmap by manipulating an optical scanning device in a hand-writing manner so as to display tracks of the optical scanning device on a screen corresponding to a movement of the optical scanning device on the displaying medium. And please refer to FIG. 2, which illustrates a frame retrieved by scanning the displaying medium shown in FIG. 1 with the optical scanning device shown in FIG. 1. As shown in FIG. 1, a displaying medium 104 is printed with a micro dotmap, where microdots printed on the micro dotmap are printed with a particular encoding method. When a user holds an optical scanning device 106 to scan the micro dotmap printed on the displaying medium 104, a frame 120 scanned by the optical scanning device 106 on the displaying medium 104 is transmitted to a screen 102 so as to display a location, which is of the held optical scanning device 106 on the displaying medium 104, on the screen 102. As shown in FIG. 2, the frame 120 scanned in FIG. 1 covers a plurality of encoding blocks 122. Each encoding block 122 is printed with a plurality of microdots 128 having different characteristics, and is separated into a header region 124 and a data region 126. The header region 124 is used for having an encoding block 122 having said header region 124 be recognizable, therefore, as shown in FIG. 2, a combination or a permutation of the plurality of microdots 128 comprised by the header region 124 of each encoding block 122 is the same. The plurality of microdots 128 comprised by each data region 126 are encoded with a particular encoding method so as to indicate a coordinate of an encoding block 122 having said data region 126 on the displaying medium 104, where the encoding method is substantially implemented on the combination or the permutation of the plurality of microdots 128 of each data region 126. As shown in FIG. 2, each encoding block 122 exclusively occupies one particular among the coordinates (x, y), (x+1,y), (x, y+1), and (x+1, y+1), each of which may be retrieved by performing a decoding procedure corresponding to the abovementioned encoding method on the plurality of microdots 128 of the data region 126 of each encoding block 122. When the optical scanning device 106 scans the frame 120, a domain of each scanned encoding block 122 is first recognized according to a data region 124 of each the scanned encoding block 122, then a plurality of microdots 128 in a data region 126 of each the scanned encoding block 122 are decoded so as to determine a coordinate of each the scanned encoding block 122 on the displaying medium 104.
Methods mentioned in FIG. 1 and FIG. 2 are primarily applied on devices such as a Braille plate. A user may hold the optical scanning device 106 to scan and move on the displaying medium 104 so as to correspondingly operate on the screen 102, or to have the screen 102 to serve as a whiteboard by directly displaying movements of the held optical scanning device 106 on the screen 102. The displaying medium 104 is a paper printed with a micro dotmap or a printable medium capable of being printed with the micro dotmap. The optical scanning device 106 may also be a conventional scanning device capable of recognizing microdots on the micro dotmap. When the user holds the optical scanning device 106, the scanned frame 120 is directly transmitted to the screen 102 having a processing unit. After the processing unit performs the abovementioned recognition and decoding procedure on the frame 120, a current location of the optical scanning device 106 on the displaying medium 104 is also displayed on the frame 120 displayed by the screen 102. After a short while, when the user holds the optical scanning device 106 to move and scan on the displaying medium 104, another frame 120 is fetched and is also processed by the processing unit of the screen 102 to be recognized and decoded.
However, in the abovementioned decoding procedure, a coordinate of each encoding block 122 covered by the frame 120 is retrieved by directly decoding the plurality of microdots 128 of the data region 126; if the user holds the optical scanning device 106 to rapidly move and scan on the displaying medium 104, a significant amount of calculations are brought since the plurality of microdots 128 of the data region 126 have to be instantly recognized and decoded. The significant amount of calculations lead to severe delays on the screen 102 in displaying the movements of the held optical scanning device 106, and bring significant inconveniences to the user.